Showerhead and showerhead manufacturing method

ABSTRACT

The present invention has the object of providing a metal showerhead lighter than previous, at a low cost. A showerhead  3  furnished with an outer cylinder  31  in which a metal plate is plastically deformed and formed into a cylindrical shape in which the base end portion thereof is left open; and a water conduit member  32  which is inserted from the open end of the base end portion side into the outer cylinder to supply hot or cold water supplied from a hose into outer cylinder  31 ; whereby a gripping portion  311  for holding outer cylinder  31  by hand is provided on the base end portion of outer cylinder  31 , and a spray portion  33  is provided in which multiple spray holes  33   b  are formed to spray hot or cold water supplied by water conduit member  32  to the front end portion side of outer cylinder  31.

TECHNICAL FIELD

The present invention relates to a showerhead capable of hand held usein a bath or shower room, and to a method for manufacturing same.

BACKGROUND ART

Proposals have been advanced for shower devices in which showerheadconstituent elements are formed of metal (Patent Document 1).Showerheads with metal constituent elements are fabricated by assemblingconstituent elements such a mouthpieces and support bodies manufacturedby casting, with ornamental plating such as nickel-chrome plating or thelike applied as needed. Since constituent elements are cast, showerheadsmanufactured by metal casting have thick walls. This means that largeamounts of raw materials are required, making material cost very high.In addition, because such showerheads are heavy, a high environmentalload is imposed due to the large quantities of CO₂ exhausted duringtransport.

PRIOR ART REFERENCES Patent References

-   Patent Document 1: Unexamined Patent Application H9-502650.

SUMMARY OF THE INVENTION Problems the Invention Seeks to Resolve

The present invention therefore has the object of providing a metalshowerhead lighter than previous, at a low cost.

Means for Resolving the Problem

In order to resolve the problems above, the claim 1 invention is ashowerhead furnished with: an outer cylinder in which a metal plate isplastically deformed and formed into a cylindrical shape in which atleast the base end portion thereof is left open, and no ornamentalplating is applied to the surface of the metal plate; and a waterconduit member inserted from the open end of the base end portion sideinto the outer cylinder to supply hot or cold water supplied from a hoseinto the outer cylinder; whereby a gripping portion for holding theouter cylinder with a hand is provided on the base end portion of theouter cylinder, and a spray portion is provided in which multiple sprayholes are formed to spray hot or cold water supplied by the waterconduit member to the front end portion side of the outer cylinder.

The outer cylinder is thus formed by plastic deformation of metal plate,so that a metal showerhead can be fabricated without ornamental plating,thus enabling the provision of a showerhead thinner and lighter thanconventional showerheads. The risk of that plating will peel off canalso be eliminated.

The invention of claim 2 is the showerhead of claim 1, whereby the frontend portion of the outer cylinder is encapsulated by welding or brazingof the metal plate or other metal member, and the spray holes are formedon the side surface on the front end portion side of the outer cylinder,such that the outer cylinder and the spray portion are integrated as asingle piece.

Thus virtually the entirety of the showerhead is comprised of an exposedmetal surface without plated ornamentation, and the metal memberpresents a unified external appearance, making it possible to present ashowerhead of unprecedented aesthetic appeal.

The invention of claim 3 is the showerhead of claim 2, whereby the frontend portion on which the spray portion is disposed is formed in a thinshape, flatter and wider than the gripping portion.

A thin unit, flatter and wider than the gripping portion at the frontend portion of the showerhead is thus formed, so that a showerhead of apreviously unavailable novel design can be provided.

The invention of claim 4 is the showerhead of claim 3, whereby in thefront end portion on which the spray portion is disposed, hot or coldwater supplied from the water guide member flows directly over the innersurface of the outer cylinder, and is supplied to the spray holes.

A separate pipe for introducing hot or cold water supplied from thewater conduit member to the spray holes is thus not required. The frontend portion of the showerhead can therefore be formed at a thickness ofapproximately 10 mm, and a showerhead with an novel design can beprovided.

Since the water conduit member is built into the showerhead grippingportion only, it is also possible to locate the center of gravity of theshowerhead on the gripping portion side. In such cases, the stability ofthe showerhead when hand-held can be improved.

The invention of claim 5 is the showerhead of claim 2, whereby the sprayportion is furnished with a spray direction determining means fordirecting hot or cold water supplied by the water conduit member at apredetermined angle from multiple spray holes.

Since water is directed by the spray direction determining means frommultiple spray holes at a predetermined angle in the spray direction, aspray appropriate for a shower may be obtained and a pleasant showerexperienced even if the spray holes are through holes drilled in a thinwalled metal plate.

The invention of claim 6 is the showerhead of claim 5, whereby the spraydirection determining means comprises a spray plate manufactured from anelastic body, furnished with multiple spray nipples on which spraynozzle holes are formed, in which the spray nipples project from each ofthe spray holes formed on the outer cylinder.

The spray nipples on the spray plate are thus formed of an elastic body,so that when scale adheres to the spray nozzle holes and clogs the spraynozzle holes, etc., the scale can be peeled off by gripping andelastically deforming the spray nipples. Because this type of sprayplate is furnished as a spray direction determining means, the outercylinder spray portion can be formed in a thin and compact manner.

The invention of claim 7 is the showerhead of claim 6, additionallyhaving spring members for pushing the spray plate onto the inner wallsurface of the outer cylinder, such that the spray nipples project fromthe spray holes due to the pressing of the spray plate onto the innerwall surface.

Since the spray plate is pressed to the inner wall surface of the outercylinder by the spring member, the spray nipples can be caused toreliably project from the outer cylinder. The spray plate is pressedonto the outer cylinder, and the spray nipples are aligned in adirection normal to the spray surface. The spray direction is thusoriented at a predetermined angle, therefore an optimal spray for ashower can be obtained, and pleasant showering is enabled.

The invention of claim 8 is the showerhead of claim 7, whereby the sprayplate is attached to the water conduit member, and by biasing of thewater conduit member by the spring member from the outer side of thewater conduit member, the spray plate is pushed onto the inner wallsurface of the outer cylinder.

The spring member thus biases the water conduit member from the outerside, therefore corrosion by hot or cold water of the spring member canbe prevented. The spring member also yields the effect of suppressingvibration of the water conduit member caused by water pressurefluctuations working inside the water conduit member.

The invention of claim 9 is the showerhead of claim 6, whereby the outercylinder is constituted by closing off the front end opening portionwith a metal member after inserting and disposing a spray plate from thefront end opening portion at that front end.

By this means the external appearance of the showerhead is madeuniformly metal, thus providing a showerhead with superior designattributes.

The invention of claim 10 is the showerhead of claim 9, whereby the endopening portion is closed by laser welding of the aforementioned metalmember.

The end opening portion of the outer cylinder is closed by laser weldingof the metal member, therefore the seam with the metal member is notnoticeable, and the aesthetic appearance of the showerhead is improved.Adhesion of dirt to the seam portion can also be prevented.

The invention of claim 11 is the showerhead of claim 1, being a sprayportion furnished with a resin spray member in which the spray holes areformed, whereby the spray member is inserted into the opening portionformed on the front end portion side of the outer cylinder.

Since the spray portion for obtaining a defined spray direction is thusa resin-formed part, a spray appropriate as a shower can be obtained,and pleasant showering is enabled. It is also possible to provideadditional shower functions in the spray member.

Also, the invention of claim 12 is the showerhead of claim 1, whereby aheat insulating means is disposed between the metal plate and the waterconduit member, and the gripping portion is disposed within the rangeover which the heat insulating means is disposed.

Since a heat insulating means is thus disposed between the metal plateand the water conduit member, the sensation of heat can be suppressedwhen the showerhead is held in the hand, even if the outer cylinder isformed of thin metal plate.

The invention of claim 13 is the showerhead of claim 1, whereby thewater conduit member is formed of a resin with a thermal conductivityratio lower than that of the metal plate.

Since the transfer of heat from the hot or cold water flowing in thewater conduit member is suppressed by the water conduit member, thesensation of heat can be suppressed when the showerhead is held in thehand, even if the outer cylinder is formed of thin metal plate.

The invention of claim 14 is the showerhead of claim 1, whereby thewater conduit member is a resin molded part formed of resin, whereby anaffixing means for affixing the water conduit member to the outercylinder is provided on the inner wall surface of the outer cylinder sothat the water conduit member disposed within the water conduit memberdoes not project beyond the front end portion of the outer cylinder.

Resin-molded members such as the water conduit member or the like forsupplying hot or cold water are thus affixed by the affixing means so asnot to move, in a state of insertion into the outer cylinder in such asway as not to project from the front end portion of the outer cylinder,therefore no line is visible in the resin at the front end portion onthe side surface of the showerhead, and a showerhead with higher designqualities than formerly available can thus be provided.

Furthermore, in order to resolve the above-described problems theinvention of claim 15 is a method for manufacturing a showerhead,having: a shell shape forming step for forming the metal pipe into apredetermined shape by plastic deformation of metal pipe; a spray holeforming step for forming multiple spray holes in the metal pipe formedinto a predetermined shape; a placement step for placing a water conduitmember through an opening portion in the metal pipe into the metal pipein which spray holes are formed; and a welding step for closing theopening portion by laser welding a metal member to the opening portion.

The external appearance of the showerhead is thus formed by laserwelding of a metal member to an opening portion of a metal pipe,therefore a uniform metal external appearance is achieved, and ashowerhead with superior aesthetics and without noticeable seams can bemanufactured. Because closing of the opening portion of the metal pipeinto which the water conduit member is inserted occurs after placementof the water conduit member inside the metal pipe formed in apredetermined shape, the degree of freedom in designing the manufacturedshowerhead can be increased.

The invention of claim 16 is the showerhead manufacturing method ofclaim 15, whereby the shell shape forming step has: a step for placingthe metal pipe in a mold for forming a bulge; a step for filling in themetal pipe disposed inside the mold with a filler; and a bulge-formingstep for expanding the metal pipe by applying pressure to the filler toplastically deform the metal pipe into the shape of the mold.

Since the metal pipe is thus formed by bulge forming, the showerhead,which has numerous curved surfaces, can be easily formed of metal.

Effect of the Invention

The present invention enables the low cost provision of a metalshowerhead with thinner walls and a lighter weight than a conventionalshowerhead. In addition, showerheads with previously unavailable noveldesigns can be provided.

BRIEF DESCRIPTION OF FIGURES

FIG. 1: A perspective drawing showing a showerhead according to a firstembodiment of the present invention.

FIG. 2: A section through X-X of the showerhead shown in FIG. 1.

FIG. 3: A section through X-X in a variant example of the showerhead ofthe first embodiment of the present invention.

FIG. 4: A perspective drawing showing a showerhead according to a secondembodiment of the present invention.

FIG. 5: A section through Y-Y of the showerhead shown in FIG. 4.

FIG. 6: An expanded section of the spray portion of the showerhead shownin FIG. 4.

FIG. 7: A partial expanded sectional diagram explaining the sprayportion in a variant example of the showerhead of the second embodimentof the present invention.

FIG. 8: A partial expanded sectional diagram explaining the sprayportion in another variant example of the showerhead of the secondembodiment of the present invention.

FIG. 9: A sectional schematic showing a showerhead according to a thirdembodiment of the present invention.

FIG. 10: A perspective drawing showing the front end portion of theshowerhead, wherein (a) shows the front end portion of the showerheadusing conventional plastic plating; and (b) shows the front end portionof the showerhead shown in FIG. 9.

FIG. 11: A sectional schematic showing a variant example of a showerheadaccording to the third embodiment.

FIG. 12: A sectional schematic showing a showerhead according to afourth embodiment of the present invention.

FIG. 13: A full sectional diagram showing a showerhead according to afifth embodiment of the present invention.

FIG. 14: A perspective view of an outer cylinder of the showerhead.

FIG. 15: A perspective view of a showerhead connecting pipe.

FIG. 16: A perspective view of a water conduit built into theshowerhead.

FIG. 17: A perspective view of a spray chamber-forming member built intothe showerhead.

FIG. 18: A perspective view of a hold-down cover built into theshowerhead.

FIG. 19: A perspective view of a spray plate built into the showerhead.

FIG. 20: A perspective view of a spring member built into theshowerhead.

FIG. 21: A diagram showing a manufacturing procedure for a showerheadaccording to a fifth embodiment.

EMBODIMENTS OF THE INVENTION

Below, referring to the attached drawings, we discuss embodiments of theshowerhead of the present invention. Note that when the same constituentelements are found in differing embodiments, they are assigned the samereference numerals and an explanation thereof is omitted.

FIG. 1 is a perspective drawing showing a showerhead according to afirst embodiment of the present invention.

The shower apparatus is constituted so that showerhead 3 is connectedvia a socket 2 to a shower hose 1 connected to the shower-side spoutingport on a mixer faucet (not shown), and showerhead 3 can be used in ahand-held manner.

The shower apparatus comprises: an outer cylinder 31 forming the shellof the showerhead 3; a water conduit member 32 inserted into and engagedwith the base end portion of outer cylinder 31 for directing hot or coldwater supplied from shower hose 1 into outer cylinder 31; and multiplespray holes 33 b engaging the front end portion of outer cylinder 31 andspraying hot or cold water in a shower form.

Outer cylinder 31 is a member formed from a metal such as SUS304. In thepresent embodiment, a pipe material (electric resistance welded pipe)obtained by roll forming a metal plate material is furthermoreplastically deformed by bulge forming or the like to expand the frontend portion of the pipe and form an outer cylinder 31. This outercylinder 31 is made as a gripping portion 311, with a diameter affordingeasy holding by hand on the base end side; and the front end portionside thereof is given a thin shape (approximately 10-15 mm), flatter andwider than gripping portion 311. Note that it is also possible to useseamless pipe material obtained by extrusion or drawing rather than rollforming.

This allows for the formation of an outer cylinder 31 with a thin wallof approximately 0.5 mm to 1 mm, thus reducing weight compared toconventional showerheads. Materials and manufacturing costs, transportcosts, and the like can thus be reduced, so that metal showerheads canbe provided at a lower cost than in the past. By reducing the weight ofthe showerhead, the volume of CO2 generated during transport can also bereduced.

Formation of outer cylinder 31 from a lustrous metal such as SUS304enables the manufacture of a high quality metal showerhead withoutornamental surface plating such as chrome plating or the like as wouldbe the case with brass. There is therefore no risk that plating willpeel, as with conventional showerheads on which metallic exteriorappearances are achieved by nickel-chrome plating or the like.

Water conduit member 32 is molded of resin; connected at one end thereofis shower hose 1, on which a water intake port 32 a is formed forreceiving the supply of hot or cold water; formed at the other end is awater discharge port 32 b for discharging the supplied hot or coldwater. Water conduit member 32 is inserted into outer cylinder 31 fromthe opposite end to that on which water discharge port 32 b is formed,and is affixed to outer cylinder 31.

Spray member 33 (spray portion) 33 is a resin injection molded part, andis attached so as to be embedded in opening portion 31 a formed in thethin body part at the front end portion of outer cylinder 31. Spraymember 33 is connected to water discharge port 32 b of water conduitmember 32, and a guide port 33 a is formed for guiding hot or cold waterinto spray member 33; multiple spray holes 33 b are also formed forspraying the guided hot or cold water onto a surface exposed on theoutside of outer cylinder 31. This spray member 33 is affixed to outercylinder 31 or to water conduit member 32 after being attached byengagement with opening portion 31 a on outer cylinder 31.

In addition, the end surface of outer cylinder 31 is exposed to theoutside without being covered by spray member 33. I.e., the thin metalend surface is exposed, and no end portion treatment such as coveringover a metallic showerhead end surface with a resin member is performed,as was done on previous showerheads with ornamental plating in order toprevent the peeling off of that plating. Thus a showerhead 3 of a cleandesign, metal on all sides, can be obtained.

A section through X-X of the shower apparatus is shown in FIG. 2.

Provided inside the showerhead, as described above, is a water conduitmember 32, inserted into outer cylinder 31 from the open end of the baseend side. This water conduit member 32 is contained within outercylinder 31 and separated by a gap of a predetermined dimension relativeto outer cylinder 31. As described above, outer cylinder 31 is a thinwalled metal with a thickness of approximately 0.5 mm to 1 mm, andtherefore easily transmits heat, however by providing a gap relative towater conduit member 32, a heat insulating air layer 341 is formed bythis gap, so there is little tendency for heat to be transmitted fromthe hot or cold water flowing in water conduit member 32. While it istrue that outer cylinder 31 is heated by body heat when showerhead 3 ishand held, that heat is impeded from transferring to water conduitmember 32. It is thus difficult to perceive the temperature of hot orcold water, and there is little tendency for the temperature of the hotor cold water to change due to body heat, when showerhead 3 is handheld.

FIG. 3 is a sectional diagram through X-X showing a variant example ofthe present embodiment.

In this variant example, heat insulation 342 with a low thermalconductivity ratio is inserted in the gap between outer cylinder 31 andwater conduit member 32 in place of air layer 341 as the insulatingmeans shown in FIG. 2. A material with a low thermal conductivity andhigh self-adhesion characteristics such as polyurethane foam isdesirable as the heat insulation 342.

While not illustrated, as another variant example it is also acceptableto impart thermal insulating characteristics to water conduit member 32itself by increasing the thickness of water conduit member 32.

In either of these variant examples, the same effect can be obtained asthat in the first embodiment.

Next we discuss a second embodiment of the showerhead of the presentinvention.

FIG. 4 is a perspective drawing showing a showerhead according to asecond embodiment.

The shower apparatus is constituted so that showerhead 4 is connectedvia a socket 2 to a shower hose 1 connected to the shower-side spoutingport on a mixer faucet (not shown), and showerhead 4 can be used in ahand-held manner.

The shower apparatus comprises an outer cylinder 41 forming the shell ofa showerhead 4, on the front end portion side of which a spray portion41 b having multiple spray holes 41 a is formed; and a water conduitmember 42 for conducting hot or cold water supplied from shower hose 1into outer cylinder 41.

Outer cylinder 41, similar to the first embodiment, is a member formedof a metal such as SUS304, for example. The front end portion of thepipe material (electric resistance welded pipe), obtained by rollforming a metal plate material, is sealed by welding or brazing of pipematerial or other metal member to make a closed pipe, then furtherplastically deformed by bulge forming or the like to expand the frontend portion of the pipe and form an outer cylinder. Alternatively, pipematerial (electric resistance welded pipe) obtained by roll forming ofmetal plate material can be plastically deformed by bulge forming or thelike, expanding and deforming the front end portion to form the outercylinder. This outer cylinder 41 is made as a gripping portion 411, witha diameter affording easy holding by hand on the base end side; and thefront end portion side thereof is made into a thin shape spray portion41 b, flatter and wider than gripping portion 411. Note that seamlesspipe material obtained by extrusion or drawing rather than roll formingcan also be used.

Outer cylinder 41 is thus formed into a thin wall of approximately 0.5mm to 1 mm, resulting in a lighter showerhead than in the past. Thisenables a reduction in materials and manufacturing costs, transportcosts, and the like so that metal showerheads can be provided at a lowercost than in the past. By reducing the weight of the showerhead, thevolume of CO2 generated during transport can also be reduced.

Because the entirety of showerhead 4 except for the part connected tothe shower hose 1 is covered with a seamless outer cylinder 41 formed ofa lustrous metal such as SUS304, a good quality metal showerhead can befabricated even without ornamentation using chrome plating or the likeas is done with brass, etc. Hence there is no risk that plating willpeel, as with conventional showerheads with metallic exteriorappearances achieved through nickel-chrome plating or the like. Exceptfor the base end portion, no seam between a resin member and a the mainbody metal member appears on the surface of showerhead 4 as the resultof installing of spray member 33 in opening portion 31 a of outercylinder 31, as was seen in the first embodiment, so there is no cakingof dirt on seams, and the showerhead conveys a highly sanitaryimpression.

As in the first embodiment, water conduit member 42 is molded of resin;connected at one end thereof is shower hose 1, on which a water intakeport 42 a is formed for receiving the supply of hot or cold water, andat the other end thereof is formed a water discharge port 42 b fordischarging supplied hot or cold water. Water conduit member 42 isaffixed to outer cylinder 41 after being inserted into outer cylinder 41from the other end portion thereof.

A section through Y-Y of the shower apparatus is shown in FIG. 5.

Provided inside the showerhead, as described above, is a water conduitmember 42, inserted into outer cylinder 41 from the open end of the baseend side. The front end of the water conduit member 42 is pressed intoouter cylinder 41 via a packing 43. Therefore hot or cold water spoutedfrom water conduit member 42 discharge port 42 b does not penetrate intothe gap between outer cylinder 41 and water conduit member 42.

Note that because a heat insulating means (air layer 341) of the sametype as the first embodiment is formed between outer cylinder 41 andwater conduit member 42, it is both difficult to difficult to perceivethe temperature of hot or cold water, and there is little tendency forthe temperature of the hot or cold water to change due to body heat,when showerhead 4 is hand held.

In the showerhead of the present invention, hot or cold water dischargedfrom water conduit member 42 discharge port 42 b is guided over theinner circumferential surface of outer cylinder 41 to spray holes 41 a.I.e., outer cylinder 41 functions as a hot or cold water conduit.

Thus with respect to showerhead 4 outer cylinder 41, the water conduitmember 42, being a resin molded part, is disposed on the base endportion side only, therefore the center of gravity of showerhead 4 ispositioned at gripping portion 411, so that the sense of stabilitygained when holding showerhead 4 by hand is increased compared toconventional showerheads.

Next, referring to figures, we explain a concrete example of the sprayportion of the showerhead.

FIG. 6 is a partial expanded sectional diagram explaining the structureof the spray portion.

As shown in FIG. 6, hot or cold water discharged from water conduitmember 42 is sprayed from spray holes 41 a. In the present embodiment,only a portion—i.e., the spray portion 41 b—is made thicker on outercylinder 41, which is formed from thin-walled metal plate of 0.5 to 1 mmthickness. This enables the spray direction to be stabilized.

However, depending on the shape of the front end portion of outercylinder 41, the flow volume of hot or cold water, etc., it may bedifficult to spray water spouted from the multiple spray holes 41 a in ashower form (fan shape) when the spray holes are drilled in athin-walled metal plate of approximately 0.5 mm to 1 mm.

To respond to this, a member can be provided to define the spraydirection, as shown in FIGS. 7 and 8.

FIG. 7 is a partial expanded sectional diagram explaining the sprayportion in a variant example of the showerhead of the second embodimentof the present invention.

In this variant example, spray portion 41 b is arranged so that a waterconduit member 51 is disposed up to the front end portion of outercylinder 41, and a rectangular opening portion 52 a is formed to fit thepitch of spray holes on outer cylinder 41, thus constituting a directionregulating portion 52 for determining the direction in which water flowsout from water conduit member 51. This direction regulating portion 52reduces the force in the advancing direction with which water flows fromthe base end portion of water conduit member 51 (the end portion on theshower hose side), thus permitting more spraying toward the center axisof spray holes 41 a than does the spray portion shown in FIG. 6.

FIG. 8 is a partial expanded sectional diagram explaining the sprayportion in another variant example of the showerhead of the secondembodiment of the present invention.

In this variant example, spray portion 41 b incorporates a spray plate61 inside outer cylinder 41 spray portion 41 b. On this spray plate 61,water passage holes 61 a, matching the pitch of the multiple spray holesformed on outer cylinder 41 and having a length greater than the wallthickness of outer cylinder 41, are formed to face in the spraydirection, and are attached in a watertight configuration on the innerwall of the side on which outer cylinder 41 spray holes 41 a are formed.Hot or cold water discharged from water conduit member 42 discharge port42 b passes through the interior of outer cylinder 41, then passesthrough water passage holes 61 a in spray plate 61 and is sprayed fromspray holes 41 a.

As noted in these variant examples, provision of items such as directionregulating portion 52 or spray plate 61 as a spray direction determiningmeans for determining the direction of spray water from a showerheadenables fan-shaped spraying of hot or cold water regardless of the wallthickness of outer cylinder 41, thereby affording a comfortable shower.

Next we discuss a third embodiment of the showerhead of the presentinvention.

FIG. 9 is a sectional schematic diagram of a showerhead pertaining to athird embodiment; FIG. 10 is a perspective drawing showing the front endportion of the showerhead, wherein (a) shows the front end portion ofthe showerhead using conventional plastic plating; and (b) shows thefront end portion of the showerhead shown in FIG. 9.

The shower apparatus of the present embodiment comprises: an outercylinder 71 forming the shell of a showerhead 7; a water conduit member72 inserted into and engaged with the base end portion of the outercylinder 71 for directing hot or cold water supplied from shower hose 1into outer cylinder 71; and a spray member 73 serving as a spray portionhaving multiple spray holes 73 b engaging the front end portion of outercylinder 71 and spraying hot or cold water in a shower form.

Outer cylinder 71 is a member formed from a metal such as SUS304. In thepresent embodiment, a pipe material (electric resistance welded pipe)obtained by roll forming a metal plate material is furthermoreplastically deformed by bulge forming or the like to expand the frontend portion of the pipe and form an outer cylinder 71. Note thatseamless pipe material obtained by extrusion or drawing rather than rollforming may also be used.

An outer cylinder 71 with a wall thickness of approximately 0.5 mm to 1mm can thus be formed, thereby achieving a lighter weight thanconventional showerheads. Material and manufacturing costs, transportcosts, and the like can thus be reduced, so that metal showerheads canbe provided at a lower cost than in the past. By reducing the weight ofthe showerhead, the volume of CO₂ generated during transport can also bereduced.

Formation of outer cylinder 71 from a lustrous metal such as SUS304enables the manufacture of a high quality metal showerhead withoutornamental surface plating such as chrome plating or the like as wouldbe the case with brass. Hence there is no risk that plating will peel,as with conventional showerheads with metallic exterior appearancesachieved through nickel-chrome plating or the like.

This outer cylinder 71 is referred to as gripping portion 711, having adiameter allowing for easy gripping by hand on the base end portionside. Also, welded onto the inner circumferential surface of outercylinder 71 is an affixing base 75, positioned a predetermined distanceaway from opening portion 71 b on the base end portion and formed of thesame material as outer cylinder 71, for affixing a water conduit member72 to outer cylinder 71.

Water conduit member 72 is molded of resin; connected at one end thereofis shower hose 1, on which a water intake port 72 a is formed forreceiving the supply of hot or cold water; formed at the other end is awater discharge port 72 b for discharging the supplied hot or cold waterto a chamber in a spray member 73. A flange 72 c extending toward theinner circumferential surface of outer cylinder 71 is formed on thewater input port 72 a side. This flange 72 c is formed to haveapproximately the same dimensions as the inner circumference of outercylinder 71 opening portion 71 b, and the thickness thereof is made thesame as the dimension from opening portion 71 b on the base end portionside up to affixing base 75.

Note that shower hose 1 is attached to water conduit member 72 waterinput port 72 a via socket 2.

Spray member (spray portion) 73 is an injection molded resin part havingwithin it a hollow space (chamber) for passing through the hot or coldwater; this is fitted onto to the front end portion of outer cylinder71. On spray member 73, multiple spray holes 73 b for spraying theintroduced hot or cold water are formed on the surface exposed on theoutside of outer cylinder 71. The shape of front end portion on spraymember 73 is formed to have approximately the same dimensions as theinner circumference of outer cylinder 71 opening portion 71 a.

These water conduit member 72 and spray members 73 are inserted intoouter cylinder 71 from opening portions 71 a, 71 b formed at both endportions of outer cylinder 71.

When assembling the showerhead, water conduit member 72 is firstinserted into outer cylinder 71, and when water conduit member 72 hitsaffixing base 75, water conduit member 72 flange 72 c and affixing base75 are joined using joining hardware 76 such as a screw or the like, andwater conduit member 72 is affixed to outer cylinder 71. Spray member 73is inserted from opening portion 71 a on the front end portion of outercylinder 71 until it hits water conduit member 72; spray member 73 andwater conduit member 72 are linked using joining hardware 74 such as ascrew or the like, and spray member 73 is affixed to water conduitmember 72. Water conduit member 72 and spray member 73 are thus affixedto outer cylinder 71.

Water conduit member 72 and spray member 73 are both formed atapproximately the same dimensions as the inner circumference of outercylinder 71 opening portions 71 a and 71 b. The distance between openingportion 71 b at the base end portion side of outer cylinder 71 andaffixing base 75 is the same dimension as the thickness of the waterconduit member 72 flange 72 c. Water conduit member 72 and spray member73 can be completely inserted into outer cylinder 71 while pluggingopening portions 71 a, 71 b. By virtue of fully inserting water conduitmember 72 and spray member 73 into outer cylinder 71, there is noexposure of water conduit member 72 and spray member 73 even when viewedfrom the side surface of outer cylinder 71.

In conventional showerheads with decorative plating, as shown in FIG.10( a), the end surface of the metallic showerhead P was covered by aresin member Q so as to prevent shock to the end portion of the platedpart, and plating was thus prevented from peeling off. However in thepresent embodiment, as shown in FIG. 10( b), the end surface of outercylinder 71 is not covered by a resin member (water conduit member 72,spray member 73), and is exposed to the outside. Therefore except forthe part on which the spray holes are formed, no resin line appears onthe showerhead front end portion, since the water conduit member 72 andspray member 73 are not exposed. Therefore design characteristics can beimproved relative to conventional showerheads.

FIG. 11 is a sectional schematic showing a variant example of theshowerhead according to the third embodiment.

The shower apparatus of this variant example comprises an outer cylinder81 forming the shell of a showerhead 8; a water conduit member 82inserted into and engaged with the base end portion of outer cylinder 81for directing hot or cold water supplied from shower hose 1 into outercylinder 81; and a spray member 83 serving as a spray portion havingmultiple spray holes 83 b engaging the front end portion of outercylinder 81 and spraying hot or cold water in a shower shape.

Outer cylinder 81 is a member formed by plastic deformation using bulgeforming or the like of a metal such as SUS304.

Outer cylinder 81 opening portion 81 a and opening portion 81 b aremachined at the time of bulge forming so that the wall thickness ofouter cylinder 81 gradually thins toward the front end portion, and istapered so that the inside diameter of outer cylinder 81 increasestoward the end portion.

Water conduit member 82 is made of resin; connected at one end thereofis the shower hose 1, on which a water intake port 82 a is formed forreceiving the supply of hot or cold water; formed at the other end is awater discharge port 82 b for discharging the supplied hot or cold waterto a chamber in a spray member 83. In addition, a sloped surface isformed on water conduit member 82 water discharge port 82 b side so asto match the above-described tapered inner circumferential surface ofouter cylinder 81.

Note that shower hose 1 is attached to water conduit member 82 waterinput port 82 a via socket 2.

Spray member (spray portion) 83 is an injection molded resin part havingwithin it a hollow space (chamber) for passing through the hot or coldwater; this is fitted onto to the front end portion of outer cylinder81. On spray member 83, multiple spray holes 83 b for spraying theintroduced hot or cold water are formed on the surface exposed on theoutside of outer cylinder 81. A sloped surface shaped to match theabove-described tapered inner circumferential surface of outer cylinder81 is formed on the front end portion of spray member 83.

This water conduit member 82 and spray members 83 are inserted intoouter cylinder 81 from opening portions 81 a, 81 b formed at both endportions of outer cylinder 81.

When assembling the showerhead, spray member 83 and water conduit member82 are joined by joining hardware 84 such as screws or the like, withwater conduit member 82 and spray member 83 inserted from openings 81 aand 81 b in outer cylinder 81. Water conduit member 82 and spray member83 are furnished with sloping surfaces matching the tapered innercircumferential surface of outer cylinder 81, so that water conduitmember 82 and spray member 83 are affixed so as not to move relative toouter cylinder 81 due to the linkage between water conduit member 82 andspray member 83.

It is of course the case that in this variant example as well, as in thethird embodiment, water conduit member 82 and spray member 83 can befully inserted into outer cylinder 81.

FIG. 12 is a sectional schematic showing a showerhead according to afourth embodiment of the present invention.

The showerhead of the present embodiment comprises: an outer cylinder 91forming the shell of a showerhead 9, on the front end portion side ofwhich a spray portion 91 b having multiple spray holes 91 a is formed;and a water conduit member 92 for conducting hot or cold water suppliedfrom shower hose 1 into outer cylinder 91.

Outer cylinder 91 is a member formed from a metal such as SUS304. Thefront end portion of the pipe material (electric resistance welded pipe)obtained by roll forming a metal plate material is sealed by welding orbrazing of pipe material or other metal member to make a closed pipe,then further plastically deformed by bulge forming or the like to expandthe front end portion of the pipe and form an outer cylinder.Alternatively, pipe material (electric resistance welded pipe) obtainedby roll forming of metal plate material can be plastically deformed bybulge forming or the like, expanding and deforming the front end portionto form the outer cylinder. This outer cylinder 91 is made as a grippingportion 911, with a diameter affording easy holding by hand on the baseend side; and the front end portion side thereof is made into a thinshape spray portion 91 b, flatter and wider than gripping portion 911.Note that seamless pipe material obtained by extrusion or drawing ratherthan roll forming may also be used.

This enables the formation of a thin wall on outer cylinder 91, with athickness of approximately 0.5 mm to 1 mm, thereby reducing weightcompared to conventional showerheads. Material and manufacturing costs,transport costs, and the like can thus be reduced, so that metalshowerheads can be provided at a lower cost than in the past. Byreducing the weight of the showerhead, the volume of CO2 generatedduring transport can also be reduced.

Because the entirety of showerhead 9 except for the part connected toshower hose 1 is covered with a seamless outer cylinder 91 formed of alustrous metal such as SUS304, a good quality metal showerhead can befabricated even without ornamentation using chrome plating or the likeas is done with brass, etc. Hence there is no risk that plating willpeel, as with conventional showerheads with metallic exteriorappearances achieved through nickel-chrome plating or the like. Exceptfor the base end portion, no member-to-member seam appears on thesurface of showerhead 9, therefore dirt does not cake on seams, and theshowerhead conveys a highly sanitary impression.

This outer cylinder 91 is referred to as gripping portion 911, having adiameter allowing for easy gripping by hand on the base end portionside. Also, welded onto the inner circumferential surface of outercylinder 91 is an affixing base 94, formed of the same material as theouter cylinder 91 a predetermined distance away from opening portion 91c, for affixing water conduit member 92 to outer cylinder 91.

Water conduit member 92 is molded of resin; connected at one end thereofis a socket 2, on which a water intake port 92 a is formed for receivingthe supply of hot or cold water; formed at the other end thereof is awater discharge port 92 b for discharging the supplied hot or coldwater. Water conduit member 92 is inserted into outer cylinder 91 fromthe opposite end to that on which water discharge port 92 b is formed,and is affixed to outer cylinder 91.

The front end of water conduit member 92 is pressed into outer cylinder91 via a packing 93. Therefore hot or cold water spouted from waterconduit member 92 spouting port 92 b does not penetrate into the gapbetween outer cylinder 91 and water conduit member 92.

In the showerhead of the present invention, hot or cold water spoutedfrom water conduit member 92 spouting port 92 b is guided over the innercircumferential surface of outer cylinder 91 to spray holes 91 a. I.e.,outer cylinder 91 functions as a hot or cold water conduit.

Thus with respect to showerhead 9 outer cylinder 91, water conduitmember 92, being a resin molded part, is disposed on the base endportion side only, therefore the center of gravity of showerhead 9 ispositioned on gripping portion 911, so that the sense of stabilitygained when holding showerhead 9 by hand is increased compared toconventional showerheads.

This water conduit member 92 is inserted into outer cylinder 91 from anopening portion 91 c formed in outer cylinder 91.

When assembling the showerhead, water conduit member 92 is firstinserted into outer cylinder 91, and when water conduit member 92 hitsaffixing base 95, water conduit member 92 flange 92 c and affixing base95 are joined using joining hardware 96 such as a screw or the like, andwater conduit member 92 is affixed to outer cylinder 91.

This water conduit member 92 is formed to have approximately the samedimensions as the inner circumference of outer cylinder 91 openingportion 91 c. The distance between opening portion 91 b of outercylinder 91 and affixing base 94 is the same dimension as the thicknessof water conduit member 92 flange 92 c. Water conduit member 92 can becompletely inserted into outer cylinder 91 while plugging openingportion 91 c. By completely inserting water conduit member 92 into outercylinder 91, water conduit member 92 is not exposed even if viewed fromthe side of outer cylinder 91. A joint surface between metal and resin,which is to say a resin line, does not therefore appear on the sidesurface of the showerhead. Therefore design characteristics can beimproved relative to conventional showerheads.

Next, referring to FIGS. 13 through 21, we discuss a showerheadaccording to a fifth embodiment of the present invention.

FIG. 13 is a full sectional diagram showing a showerhead according to afifth embodiment of the present invention.

As shown in FIG. 13, showerhead 100 of the present embodiment is ashowerhead for a hand shower, used by connecting to a shower hose 1 viaa socket 2. Outer cylinder 102, which forms a housing for showerhead100, is constituted by plastic deformation of SUS304 steel plate, and nodecorative plating is applied to the surface thereof. A spray portion104 for spraying hot or cold water is disposed on the front end portionof showerhead 100, and a gripping portion 106 is formed on the baseportion side thereof to allow users to grip same with fingers.

As shown in FIG. 13, showerhead 100 has an outer cylinder 102, aconnecting pipe 108 attached to this outer cylinder 102, a water conduit110 disposed inside outer cylinder 102, a spray chamber-forming member112, a hold-down cover 114, and a spring member 118. Here water conduit110, spray chamber-forming member 112, and hold-down cover 114 functionas a water conduit member for supplying hot or cold water supplied fromshower hose 1 into outer cylinder 102.

Next, referring to FIGS. 14 through 20, we discuss the structure of eachpart of a showerhead 100 according to a fifth embodiment of the presentinvention.

FIG. 14 is a perspective view of outer cylinder 102; FIG. 15 is aperspective view of connecting pipe 108; FIG. 16 is a perspective viewof water conduit 110; FIG. 17 is a perspective view of spraychamber-forming member 112; FIG. 18 is a perspective view of hold-downcover 114; FIG. 19 is a perspective view of spray plate 116; FIG. 20 isa perspective view of spring member 118.

As shown in FIG. 14, outer cylinder 102 is a cylindrical member made ofmetal; base end portion 102 a and front end opening portion 102 bthereof are left open. Base end portion side of outer cylinder 102 isformed to be generally circular in section, and constitutes grippingportion 106 of showerhead 100. The front end portion side, on the otherend, is flatter than the gripping portion, and constitutes a sprayportion 104 having a broad and generally rectangular section. Betweenthe generally circular section on the base end side and the generallyrectangular section on the front end portion side, there is a smoothtransition from a circular to a flattened rectangular section. Inaddition, multiple spray holes 102 c are formed on the wide side surfaceof outer cylinder 102. As will be described below, front end openingportion 102 b is closed by welding a metal member 102 d after placementof a water conduit member inside outer cylinder 102.

As shown in FIG. 15, connecting pipe 108 is a generally cylindricalmember made of metal. A generally disk-shaped flange portion 108 a isformed on an intermediate portion of connecting pipe 108; the openingportion on the base end side of outer cylinder 102 is covered by weldingthe outer perimeter of this flange portion 108 a to base end portion 102a on outer cylinder 102. Also, a male screw portion 108 b is formed atthe base end portion of connecting pipe 108, and shower hose 1 is joinedto showerhead 100 by the screwing of socket 2 onto this male screwportion 108 b (FIG. 13). Furthermore, a cylindrical water conduitconnecting portion 108 c is formed on the front end side of connectingpipe 108, and communication between connecting pipe 108 and waterconduit 110 is established by the insertion of this water conduitconnecting portion 108 c into the base end portion of water conduit 110.There is also a channel 108 d formed on the outer perimeter of waterconduit connecting portion 108 c; water tightness is secured betweenconnecting pipe 108 and water conduit 110 by disposing an O ring in thischannel 108 d (FIG. 13).

As shown in FIG. 16, water conduit 110 is an elongated cylindricalmember made of resin. The base end portion side of water conduit 110 isformed to be generally circular in section, and the front end portionside thereof is formed to be generally rectangular in section. Asdescribed above, connecting pipe 108 is inserted into a base end portion110 a on water conduit 110, while a water conduit connecting portion 112a (FIG. 17) on spray chamber-forming member 112 is inserted into frontend portion 110 b of water conduit 110 and joined (FIG. 13).

As shown in FIG. 17, spray chamber-forming member 112 is a generallythin, box-shaped member, and a generally cuboid spray chamber is formedon the interior thereof by the attachment of hold-down cover 114. Awater conduit connecting portion 112 a is formed at the base end side ofspray chamber-forming member 112, and a spray chamber portion 112 b isformed on the front end side thereof. A connecting portion 112 c isformed to establish communication between water conduit connectingportion 112 a and spray chamber portion 112 b.

Water conduit connecting portion 112 a is a cylinder with a generallyrectangular section which communicates with water conduit 110 byinsertion into front end portion 110 b of water conduit 110. A channel112 d is formed on the outer perimeter of water conduit connectingportion 112 a; water tightness is secured between water conduitconnecting portion 112 a and water conduit 110 by disposing packing inthis channel 112 d (FIG. 13).

Connecting portion 112 c is a flow path connecting water conduitconnecting portion 112 a and spray chamber portion 112 b, and is formedto spread in a tapered shape from water conduit connecting portion 112 atoward spray chamber portion 112 b.

Spray chamber portion 112 b is formed to be generally cuboid, and isfurnished with multiple round holes 112 e on its bottom surface. Each ofthe round holes 112 e is positioned to align with each of the sprayholes 102 c provided on outer cylinder 102 when spray chamber-formingmember 112 is placed within outer cylinder 102. Connecting portion 112 cand the open ceiling surface of spray chamber portion 112 b is closedoff by hold-down cover 114 (FIG. 18).

As shown in FIG. 18, hold-down cover 114 is a flat member with anedging, constituted to close off the open portion of spraychamber-forming member 112. Hold-down cover 114 has a flat sheet-shapedportion 114 a and an edging portion 114 b formed around the perimeteredge portion of sheet-shaped portion 114 a. The insertion of edgingportion 114 b into the open portion of spray chamber-forming member 112results in covering of the open portion by sheet-shaped portion 114 a.Furthermore, multiple pins 114 c are disposed on sheet-shaped portion114 a facing toward the inside of the spray chamber. Pins 114 c aredisposed in a lattice on sheet-shaped portion 114 a; the front endsthereof are arranged to contact the back surface of spray plate 116,which is disposed inside the spray chamber (FIG. 13). The rows andcolumns of the arrayed pins 114 c are arrayed to be positioned betweenthe rows and columns of round holes 112 e (spray holes 102 c) arrayed ina lattice. Spray plate 116 is thus held down by pins 114 c without pins114 c blocking spray holes 102 c.

Furthermore, a channel 114 d is formed on the outer perimeter of edgingportion 114 b; by disposing packing 120 (FIG. 13) in this channel 114 d,water tightness is secured between spray chamber-forming member 112 andhold-down cover 114.

As shown in FIG. 19, spray plate 116, being a spray direction regulatingmeans, is a plate-shaped member made of silicon rubber, serving as anelastic body. Multiple spray nipples 116 a arrayed in a lattice areprovided on this spray plate 116. Spray nipples 116 a are generallycylindrical, and are positioned to align with each of the round holes112 e provided on spray chamber-forming member 112, and with each of thespray holes 102 c provided on outer cylinder 102. Therefore when sprayplate 116 is disposed on the bottom surface of spray chamber-formingmember 112, spray nipples 116 a project outside of outer cylinder 102,passing through round holes 112 e on spray chamber-forming member 112and spray holes 102 c on outer cylinder 102. Spray nozzle holes 116 bare provided on the center axis line of each of the respective spraynipples 116 a. Hot or cold water supplied into the spray chamber issprayed through these spray nozzle holes 116 b. The direction in whichhot or cold water is sprayed is generally regulated by passage of hot orcold water through each of the spray nozzle holes 116 b, therefore sprayplate 116 functions as a spray direction regulating means. When sprayplate 116 is disposed on the bottom surface of spray chamber-formingmember 112 and hold-down cover 114 is attached spray chamber-formingmember 112, the front ends of pins 114 c provided on hold-down cover 114press the rear surface of spray plate 116 (the side on which spraynipples 116 a are disposed). This causes spray plate 116 to be pressedand sealed onto the bottom surface of spray chamber-forming member 112.

As shown in FIG. 20, spring member 118 comprises thin metal plate, whichis caused to act as a plate spring by bending a portion of the metalplate. Spring member 118 has a flat portion 118 a and a bent portion 118b, being the bent portion at the front end of flat portion 118 a. Flatportion 118 a is disposed so as to be superimposed on hold-down cover114, and is formed to have generally the same shape as hold-down cover114. Furthermore, cutouts are provided on flat portion 118 a, thusforming five rectangular plate springs 118. Each of the plate springs118 is a cantilevered beam molded into a “V” shape at two intermediatespots, one end of which is connected to flat portion 118 a.

The spray chamber is externally biased by overlaying spring member 118onto the rear surface of hold-down cover 114 and causing the bentcorners of plate springs 118 to contact the inner wall surface on therear side of outer cylinder 102 (FIG. 13). Thus hold-down cover 114, aswell as spray chamber-forming member 112 attached thereto, and sprayplate 116, are pressed into the inner wall surface on the front surfaceside of outer cylinder 102. Through the pressing of spray plate 116 intothe inner wall surface of outer cylinder 102 via hold-down cover 114 byspring member 118, spray nipples 116 a on spray plate 116 are reliablymade to project out from spray holes 102 c.

Next, referring to FIG. 21, we discuss a method for manufacturing ashowerhead 100 according to the present embodiment. FIG. 21 is a diagramshowing the procedure for manufacturing showerhead 100.

First, in step S1 of FIG. 21, stainless steel flat plate is plasticallydeformed by roll forming and machined into a cylindrical shape.

Next, in step S2, the butt surfaces of the stainless plate plasticallydeformed into a cylindrical shape are joined by welding. A raw stainlesspipe, being a metal pipe, is thus formed.

In step S3, a stainless plate is welded to the front end of the formedpipe to close the front end of the pipe. A blanked off pipe is thusformed. Note that in the present embodiment, steps S1 through S3 aboveare referred to as the metal pipe forming step.

Next, in step S4, welding marks on the blanked off pipe are removed bygrinding.

In step S5, the blanked-off pipe is bent to form a bent pipe.

In step S6, the front end portion of the bent pipe is deformed into aflattened shape by press forming.

Next, in step S7, the bent pipe, deformed into a flat shape, isbulge-formed. I.e., the bent pipe, deformed into a flat shape, is loadedinto a bulge-forming mold, and the mold is closed. Furthermore, a fillerof some liquid or the like is injected into the bent pipe and the fillersubjected to high pressure at a maximum of approximately 200 MPa,expanding and plastically deforming the bent pipe. This causes thebulge-formed bent pipe to be formed into a bulged-formed product withapproximately the same shape as the mold cavity. Note that in thepresent embodiment, steps S5 through S7 above are referred to as theshell forming step.

In step S8, immediately after plastic deformation by bulge forming,piercing is conducted with high pressure applied to the filler in themold. In the piercing step, spray holes 102 c are formed by theinsertion of piercing pins from outside the bulge-formed product. Aspray hole-formed product is thus obtained. Note that in the presentembodiment, step S8 is referred to as the spray hole forming step.

Next, in step S9, the blanked-off portion of the front end of the sprayhole-formed product is cut off, thus opening the front end portion. Apre-machined product is thus obtained. Note that in the presentembodiment, step S9 is referred to as the cutting step.

In step S10, surface finishing is carried out by grinding the surface ofthe pre-machined product. This results in the formation of an outercylinder 102 on which the front end portion is open.

Next, in step S11, water conduit members such as spray chamber-formingmember 112 are disposed inside the outer cylinder 102 on which the frontend portion is open. I.e., after disposing spray plate 116 in spraychamber-forming member 112, hold-down cover 114 is attached to the openportion of spray chamber-forming member 112, mediated by packing 120, toform an assembled unit. This assembled unit is inserted and placed fromthe open portion at the front end of outer cylinder 102. When theassembled unit is inserted up to a predetermined position on the outercylinder 102, spray nipples 116 a on spray plate 116 are aligned withspray holes 102 c on outer cylinder 102, and spray nipples 116 a projectout from spray holes 102 c. In this state, spring member 118 is insertedbetween hold-down cover 114 and the inner wall surface of outer cylinder102. When spring member 118 is inserted, hold-down cover 114 is presseddown by the biasing force of spring member 118, and spraychamber-forming member 112 is pressed into the inner wall surface on theopposite side from spring member 118 on outer cylinder 102. Theassembled unit is thus accurately positioned and affixed within outercylinder 102.

At the same time, connecting pipe 108 is inserted through an O ring intothe base end portion 110 a of water conduit 110. Next, water conduit 110attached to connecting pipe 108 is inserted from the base end portion102 a opened on outer cylinder 102. When water conduit 110 is insertedto a predetermined position, the water conduit connecting portion 112 aof spray chamber-forming member 112 is inserted within front end portion110 b on water conduit 110. Because of the installation of packing inwater conduit connecting portion 112 a, water conduit connecting portion112 a and water conduit 110 are connected in a watertight fashion whenwater conduit connecting portion 112 a is received into the front endportion 110 b of water conduit 110. Note that in the present embodiment,step S11 is referred to as the positioning step.

Next, in step S12, a metal member is laser-welded to the open portion atthe front end of outer cylinder 102, closing the open portion. Inaddition, connecting pipe 108 flange portion 108 a is welded to outercylinder 102 base end portion 102 a to complete the showerhead 100. YAGlaser welding or fiber laser welding are preferably used for laserwelding. A good welded surface can thus be obtained, and grinding of thelaser welded portion can be omitted. Note that in the presentembodiment, step S12 is referred to as the welding step.

Next, referring to FIG. 13, we discuss the operation of showerhead 100according to the present embodiment.

First, showerhead 100 of the present embodiment is used by connection toshower hose 1 via socket 2. Hot or cold water supplied from shower hose1 flows into water conduit 110 through connecting pipe 108. Hot or coldwater flowing into water conduit 110 passes through water conduitconnecting portion 112 a on spray chamber-forming member 112 and flowsinto a spray chamber, being a space constituted between spraychamber-forming member 112 and hold-down cover 114. Hot or cold waterflowing into the spray chamber passes through spray nozzle holes 116 bdisposed on spray plate 116 and is sprayed. The direction of the sprayedhot or cold water is regulated by spray nozzle holes 116 b. Siliconrubber spray plate 116 is pressed into the bottom surface of spraychamber-forming member 112 by multiple pins 114 c disposed on hold-downcover 114, therefore hot or cold water in the spray chamber entersbetween spray plate 116 and the bottom surface of spray chamber-formingmember 112, and leakage from the gap between spray nipples 116 a andround holes 112 e can be prevented. If impurities in the hot or coldwater adhere as scale to the interior of spray plate 116, blocking spraynozzle holes 116 b, the scale can be removed by gripping the spraynipples 116 a projecting out from outer cylinder 102 with fingers anddeforming them.

Using the showerhead 100 of the fifth embodiment of the presentinvention, spray nipples 116 a of spray plate 116 can be formed of asilicon rubber elastic body, therefore when scale adheres to spraynozzle holes 116 b resulting in clogging or the like of spray nozzleholes 116 b, the scale can be peeled off by grasping spray nipples 116 awith the fingers and plastically deforming same. With the provision ofsuch a spray plate 116 as a spray direction regulating means, showerhead100 spray portion 104 can be formed in a thin and compact manner.

Using the showerhead 100 of the present embodiment, spray plate 116 ispressed together with spray chamber-forming member 112 and hold-downcover 114 by spring member 118 into the inside wall surface of outercylinder 102, so that spray nipples 116 a reliably project out from theouter cylinder.

Furthermore, using the showerhead 100 of the present embodiment, springmember 118 biases water conduit members such as hold-down cover 114 fromthe outside of the spray chamber, therefore the time during which springmember 118 is in contact with hot or cold water is short, and corrosionby hot or cold water of spring member 118 can be prevented.

In addition, using the showerhead 100 of the present embodiment, theexternal appearance of showerhead 100 is uniformly metal, thus achievinga showerhead 100 with superior design attributes.

In addition, using the showerhead 100 of the present embodiment, frontend opening portion 102 b on the outer cylinder is closed by laserwelding of metal member 102 d, therefore the seam with metal member 102d is not prominent, and the aesthetic appearance of showerhead 100 canbe improved. Adhesion of dirt to the seam portion can also be prevented.

Using the manufacturing method for the embodiment showerhead of thepresent invention, the external appearance of showerhead 100 isconstituted by laser welding of a metal member 102 d to front endopening portion 102 b on outer cylinder 102, being a metal pipe,therefore a showerhead 100 can be manufactured with a uniform metalexternal appearance, and with a superior aesthetics free of noticeableseams. After disposing water conduit members such as spraychamber-forming member 112 inside an outer cylinder 102 formed to apredetermined shape, the front end opening portion 102 b on outercylinder 102, into which a water conduit member has been inserted, isclosed. The shape of the water conduit member is thus not prone to belimited by the shape of outer cylinder 102, and the degree of freedom indesigning the manufactured showerhead 100 is increased.

Using the manufacturing method for the embodied showerhead, outercylinder 102, being a metal pipe, is formed by bulge forming, thereforethe entire body of a showerhead 100 with many curved surfaces can beeasily formed of metal.

We have described embodiment of the present invention above. However thepresent invention is not limited to the these descriptions.

For example, we discussed the example of SUS304 as metal plate forforming the outer cylinder, but other metal materials may be used asappropriate so long as they have a favorable appearance and are durablerelative to water.

With respect to the structure for affixing the water conduit member andspray member to the outer cylinder, our explanation was based on thethird embodiment and the fourth embodiment variant thereon, but it isalso possible, for example, by crimping the front end portion of theouter cylinder with the water conduit member or spray member inserted inthe outer cylinder, to adopt a structure in which the water conduitmember or spray member is affixed so as not to move relative to theouter cylinder.

Each of the elements comprising each of the above-described embodimentscan be combined to the extent technically feasible; these combinationsare also included in the scope of the present invention so long as theyinclude the features of the present invention.

EXPLANATION OF REFERENCE NUMERALS

-   1: shower hose-   2: socket-   3: showerhead-   31: outer cylinder-   31 a: opening portion-   311: gripping portion-   32: water conduit member-   32 a: water intake port-   32 b: water discharge port-   33: spray member (spray portion)-   33 a: guide port-   33 b: spray holes-   341: air layer (heat insulating means)-   342: heat insulation (heat insulating means)-   4: showerhead-   41: outer cylinder-   41 a: spray holes-   41 b: spray portion-   411: gripping portion-   42: water conduit member-   42 a: water intake port-   42 b: water discharge port-   43: packing-   51: water conduit member-   52: direction regulating portion (spray direction regulating means)-   52 a: opening portion-   61: spray plate (spray direction regulating means)-   61 a: water passage holes-   7: showerhead-   71: outer cylinder-   71 a, 71 b: opening portions-   711: gripping portion-   72: water conduit member-   72 a: water input port-   72 b: water discharge port-   72 c: flange-   73: spray member-   73 b: spray holes-   74: joining hardware-   75: affixing base-   76: joining hardware-   8: showerhead-   81: outer cylinder-   81 a, 81 b: opening portion-   82: water conduit member-   82 a, 82 b: water intake ports-   83: spray member-   83 b: spray holes-   84: joining hardware-   9: showerhead-   91: outer cylinder-   91 a: spray holes-   91 b: spray portion-   911: gripping portion-   92: water conduit member-   92 a: water intake port-   92 b: water discharge port-   93: packing-   94: affixing base-   95: joining hardware-   100: showerhead-   102: outer cylinder-   102 a: base end portion-   102 b: front end opening portion-   102 c: spray holes-   102 d: metal member-   104: spray portion-   106: gripping portion-   108: connecting pipe-   108 a: flange portion-   108 b: male screw portion-   108 c: water conduit connecting portion-   108 d: channel-   110: water conduit-   110 a: base end portion-   110 b: front end portion-   112: spray chamber-forming member-   112 a: water conduit connecting portion-   112 b: spray chamber portion-   112 c: connecting portion-   112 d: channel-   112 e: round holes-   114: hold-down cover-   114 a: sheet-shaped portion-   114 b: edging portion-   114 c: pins-   114 d: channel-   116: spray plate (spray direction regulating means)-   116 a: spray nipples-   116 b: spray nozzle holes-   118: spring member-   118 a: flat portion-   118 b: bent portion-   118 c: plate springs-   120: packing

1. A showerhead, comprising: an outer cylinder formed in a cylindrical shape by plastically deforming a metal plate, causing at least the end portion on the base end portion side to be open, and not applying decorative plating to the surface of the metal plate; and a water conduit member, inserted from the open end on the base end portion side into the outer cylinder, for supplying hot or cold water supplied from a shower hose into the outer cylinder; wherein a gripping portion for holding the outer cylinder by hand is provided on the base end portion side of the outer cylinder; and a spray portion, in which multiple spray holes are formed for the purpose of spraying hot or cold water supplied from the water conduit member, is provided on the front end portion side of the outer cylinder.
 2. The showerhead according to claim 1, wherein the spray portion is constituted by forming spray holes on the side surface on the front end portion side of the outer cylinder.
 3. The showerhead according to claim 2, wherein the front end portion on which the spray portion is disposed is formed in a thin shape, flatter and wider than the gripping portion.
 4. The showerhead according to claim 3, wherein in the front end portion on which the spray portion is disposed, hot or cold water supplied from the water conduit member flows directly over the inner surface of the outer cylinder, and is supplied to the spray holes.
 5. The showerhead according to claim 2, wherein the spray portion is furnished with a spray direction determining means for directing hot or cold water supplied by the water conduit member at a predetermined angle from multiple spray holes.
 6. The showerhead according to claim 5, wherein the spray direction determining means comprises a spray plate manufactured from an elastic body, furnished with multiple spray nipples on which spray nozzle holes are formed, whereby the spray nipples project from each of the spray holes formed on the outer cylinders.
 7. The showerhead according to claim 6, further comprising spring members for pushing the spray plate onto the inner wall surface of the outer cylinder, such that the spray nipples project from the spray holes due to the pressing of the spray plate onto the inner wall surface.
 8. The showerhead according to claim 7, wherein the spray plate is attached to the water conduit member, and the spray plate is pushed onto the inner wall surface of the outer cylinder by the biasing of the water conduit member by the spring member from the outer side of the water conduit member.
 9. The showerhead according to claim 6, wherein the outer cylinder is constituted by closing off the front end opening portion with a metal member after inserting and disposing a spray plate from the front end opening portion at that front end.
 10. The showerhead according to claim 9, wherein the front end opening portion is closed by laser welding of the metal member.
 11. The showerhead according to claim 1, further comprising a spray member made of resin, on which spray holes are formed; and wherein the spray portion is formed by inserting the spray member into the opening portion formed on the front end portion side of the outer cylinder.
 12. The showerhead according to claim 1, wherein a heat insulating means is provided between the metal plate and the water conduit member; and the gripping portion is provided within the range over which the heat insulating means is provided.
 13. The showerhead according to claim 1, wherein the water conduit member is formed of a resin with a thermal conductivity ratio lower than that of the metal plate.
 14. The showerhead according to claim 1, wherein the water conduit member is a resin molded part formed of resin, wherein an affixing means for affixing the water conduit member to the outer cylinder is provided on the inner wall surface of the outer cylinder so that the water conduit member disposed within the outer cylinder conduit member does not project beyond the front end portion of the outer cylinder.
 15. A method for manufacturing a showerhead, comprising steps of: forming a metal pipe into a predetermined shape by plastic deformation of the metal pipe; forming multiple spray holes in the metal pipe formed in a predetermined shape; placing a water conduit member through an opening portion in the metal pipe into the metal pipe in which spray holes are formed; and closing the opening portion by laser welding of a metal member to the opening portion.
 16. The method according to claim 15, wherein the step for forming the metal pipe includes steps of: placing the metal pipe in a mold for bulge forming; filling the interior of the metal pipe placed inside the mold with a filler; and expanding the metal pipe by applying pressure to the filler to plastically deform the metal pipe into the shape of the mold. 